To strike a male in the groin as a form of horseplay.
"Dude, I nutchecked Miguel so hard he fell."
"Nick P. tried to nutcheck me, but he missed and hit my thigh."
A check received from the state, for a person that has been diagnosed mentally unstable.
The man was in a much happier mood leaving the bank since his nutcheck had cleared.
The woman was over joyed since her nutcheck had arrived in the mail.